I just yesterday 20mg and it made me calm and focused for about 7 hours with ups and downs.
Today i took the same and its much more powerful feel high somewhat 9th hour on it and slowly going down, studied 4 hours without problem even tho i couldnt study for 10 min before and feel intense somewhat unlike yasterday. So why does it happen that one day is stronger then others, kinda makes it hard to see what the right dosage is for titration purposes.

maybe its a food issue?

do you eat before, or within an hour after taking it? some people have better effects with it on an empty stomach. if i eat anything within the same time as taking it, it generally has a lesser effect on me throughout the day as far as focus/attention is concerned, but it takes a lot more time to wear off completely.

also, dont eat/drink anything acidic for a few hours before OR after taking it, for a lot of people that tends to lessen the effects of it.

hope this helps, i'm sure others will have a lot more to add :)

Is it the Adderall XR?

I ask because I read somewhere that Adderall XR in some people can remain active in your system for 24 hours due to the long action and build up as a result of it still being in your system and active. I don't know if that's valid but I read it somewhere and I will try to look for a shortcut to post if I get around to looking for it.

I feel the effects of the XR (don't take the IR) are mostly inconsistent as well. I felt this even more when I was on a higher dosage. Sometimes it lasts what seems to be all day and night, sometimes much less.
I agree that what you eat or drink affects how it works and how long it lasts in general.
I lowered my dose recently and feel less of the ups and downs, but I can never tell how long the thing will last. Lately it's lasting a long time, for me.
From my experience, the higher the dose, the more you feel it, that includes the inconsistent effects. If you like a milder effect, try lowering your dose. Maybe 10 mg instead of 20. You can do this by getting empty pills and filing them with half the contents of your Adderall pill ;) No need to change your prescription with the doc. See if you like it better that way.

I don't take Adderall anymore to study but rather to help me in the job hunt process, but when i did take it to study I found it worked the best for me when I would drink two parts water to every one part of caffeinated drink. For some reason I have to drink at TON fluids on Adderall. I also found it varied depending on the difficulty of the material I was on. I would have to remind myself I'm not a 4.0 student so if I dont understand everything, its ok. Also, i found I did worse on objective exams while on Adderall as i would tend to way over analyze the question, so by my senior year I would only take it for written exams. Does wonders for written analysis for me.

Interesting to know that adderall XR's inconsistency is a common problem. Some factors that dramatically effect the duration and efficacy for me:

- sufficient sleep (>7 hr. per night)
- sufficient hydration
- eating a balanced diet and eating often
- other medication/ vitamins
- morning exercise 3x per week

While on Adderall, even OTC analgesics like tylenol make it difficult for me to fall asleep by midnight, and I'm deligent about taking my 4:00 PM IR dose on schedule...

Interestingly, I find that drinking a few tall galsses of soy milk (high tyramine content) about an hour before bedtime helps me get to sleep faster.

I think everything written by umami in the previous post is excellent advice. For me and my meds sleep is the number 1 issue. With meds I am consistently more active throughout the day and I no longer take daytime naps.

Going to sleep at the same time I used to, caused the meds to work poorly. It took me a couple of months to make the connection. Now I go to sleep about 1-2 hours earlier than I used to and the effects of the meds are much more even.

I have the same results sometimes. It all depends on if I eat beforehand or what I eat during the day.

Taking a pill on an empty stomach is not good, unless it is a thyroid pill or such,it is usually not a good thing to do. Taking pills with food won't affect the pills but it will keep your stomach from possibly being at the least upset from the pills. I not only am directed by my Dr to take food with some of my medication, but also I take a tablet expressly to protect my stomach from the meds I take. The reason is that before mistakes like this caused ulcers in my stomach.

Taking a pill on an empty stomach is not good, unless it is a thyroid pill or such,it is usually not a good thing to do. Taking pills with food won't affect the pills but it will keep your stomach from possibly being at the least upset from the pills. I not only am directed by my Dr to take food with some of my medication, but also I take a tablet expressly to protect my stomach from the meds I take. The reason is that before mistakes like this caused ulcers in my stomach.Adderall can be taken with or without food. I take mine on a empty stomach one hour before I get up and have had NO problems. While taking SOME types of pills on an empty stomach is not reccommended, adderall is not one of them.

Anything you take on an empty stomach is affected more by stomach acidity then when you take it an hour after eating. And of course we know the reliationship with adderall and acid. :)